Braking means for a rotary hoist



March 21, 1967 H. WO RKMAN 3,310,290

BRAKING MEANS FOR A ROTARY IiIOIST Filed May 10, 1965 INVENTOR. LAWRENCEH. WORK/WAN W ZZ/ A T TOR/V5 Y United States Patent 3,310,290 BRAKINGMEANS FGR A ROTARY HOET Lawrence H. Workman, Muskegon, Mich. assignor toGardner-Denver Company. a corporation of Delaware Filed May 10, 1965,Ser. No. 454,561 2 Claims. (Cl. 254-168) This invention generallyconcerns hoists and, more particularly, an improved structural andfunctional relationship of a rotary hoist motor and a load brakingdevice.

An object of the invention is the provision of a hoist body having ahollow casing member providing a common housing for a rotary drive motorand a load brake wherein the motor and the brake are advantageouslydisposed in closely spaced, coaxial relation to one another.

Another object is to provide a hoist motor and adjustable load brake ina common housing member whereby the motor and other operating elementsof the hoist may be easily assembled and disassembled with respect tothe brake without disturbing a preset adjustment of the braking forceprovided by the brake.

Another aspect of the invention is the provision of a drum-type brakefor a rotary hoist which is supported and journaled by a hoist casingmember so that braking forces which are radially applied to the brakedrum are borne by the casing member rather than by the motor bearings orother operating parts of the hoist.

Yet another object is the provision of a hoist which is characterized bylight weight and compactness, by economical manufacture and maintenance,and by simplicity and reliability in operation.

These and other objects and advantages will appear upon reading thefollowing description and appended claims and upon considering inconjunction therewith the accompanying drawings, in which:

FIG. 1 is a perspective view of a hoist embodying the present invention;

FIG. 2 is a section taken generally along lines 2-2 of FIG. 3; and

FIG. 3 is an enlarged fragmentary section taken generally along lines3-3 of FIG. 2.

FIG. 1 illustratues a hoist having a body, indicated in its entirety bynumeral 10, including a gear housing 12, a motor housing 14 and aclosure member 16. Integrally formed on the exterior of the gear hOusing12 are two projecting bosses 18 and 20 which respectively provide afair-lead for a hoist cable 22 and a mount for a load hook 24. The loadhook 24 and the cable 22 are vertically aligned and are laterally offsetfrom the vertical center line of the hoist body 10. The upper end of thecable 22 is connected to a support book 26 by means of a swivel plate28; and, the support book 26 is adapted to engage with any suitableoverhead member, not shown. As best shOWn in FIG. 3, the gear housing 12is substantially bellshaped and houses in its interior rotative driveelements of the hoist. A lipped flange 30 of the gear housing 12matingly receives a radially projecting flange 32 of the motor housing14 and is attached thereto for ready removal by the threaded fasteners34. A cylindrical cavity 36 extends nearly the full length of the motorhousing 14 and is substantially closed at its inner end by a transverseWall 38 having a central aperture 40 opening therethrough. Theaforementioned closure member 16 is removably secured to one end of themotor housing 14 by suitable fasteners 42 for closing the outer end ofthe cavity 36. Integrally formed with the closure member 16 are arm 44and a horizontally disposed handle 46, the latter being laterally spacedfrom the hoist body 10 and intersecting the arm 44 at approximatelyright angles to form an elbow. By removing the fasteners 42, the closuremember 16 may be rotated 180 to facilitate grasping of the handle 46 bya left-handed operator.

Referring to FIG. 3, an expansible chamber pressure fluid motor of theconventional rotary vane type is generally designated by numeral 48 andis removably mounted in cavity 36 of the motor housing member 14. Themotor 48 comprises a cylinder 50 mounting end plates 52 and 54, thelatter end plate carrying an antifriction bearing 56 which rotativelyjournals a hollow driving sleeve extension 58 of the motor rotor 60. Theconstruction and operation of this type of pressure fluid motor is wellknown and need not be described herein in detail. For the purpose ofsupplying motive fluid to the motor 4-8, a flexible conduit 62 whichencircles the cable 22 is coupled to the handle 46 by a suitable fitting64 and is anchored at its upper end to the swivel plate 28. Pressurefluid is supplied from a source, not shown, to a fitting 66 at the upperend of the conduit 62. Valve actuating levers 68 and 70 are pivotallymounted near the juncture of the arm 44 and the handle 46 and arealternately depressible for actuating a pair of fluid supply valves, notshown, disposed within the handle 46. These supply valves are operablein a conventional manner to communicate motive fluid from conduit 62 toinlet ports of the motor 48 through suitable fluid passages, not shown,in the closure member 16. Other passages, not shown, in the motor casing14 and the closure member 16 return motor exhaust to a bore 72 throughthe handle 46 for venting the exhaust to atmosphere. By digitallymanipulating the valve actuating levers 68 and 70, the hoist operatorcan effect reversible rotation of the motor 48 and, as will beunderstood from the following description, the hoist motor can becontrolled in this manner for vertically raising and lowering the hoistbody 10 and a load attached to the hook 24.

The rotary power output of the motor 48 is imparted to a pinion shaft 74which has a splined end '76 held in relatively reciprocable, butnonrotatable relationshi with mating splines on the interior wall of thesleeve extension 58 of the rotor 66. The pinion shaft 74 extendscoaxially from the motor 48 into the gear housing 12 into rotary drivingengagement with the input elements of a conventional speed reducing geartrain, not shown, the output element of which rotatively drives a cablereel 77 comprising joined plates 78 and 80. As shown in FIG. 3, the loadbearing cable 22 is wound about the reel 77 within an annular groovedefined between the plates 78 and 80. Plate 78 is journaled by a bearing82 carried by the gear housing 12; and, plate is journaled by a bearing84 carried by the transverse wall 38.

A load brake assembly for the hoist includes a rotary brake drum 86, abrake shoe 88, a brake spring and a brake releasing piston 92. The brakedrum 86 is located within the cavity 36 generally between the motor endplate 54 and the transverse wall 38 and in coaxial relation with themotor 48 and the pinion shaft 74. The brake drum 86 has an internallysplined center opening and an extension or boss 94 which is supportedand rotatively journaled in the aperture 40 of wall 38 by means of abearing 96. The drum 86 coaxially surrounds the splined end 76 of thepinion shaft 74 in relatively reciprocable, but nonrotatablerelationship. As viewed in FIG. 2, the brake shoe 8% is in the shape ofa reversed C and is pivotally attached at one end to the transverse wall38 by a pin 98 which penetrates a bent over En of the shoe. The otherend of the shoe 88 carries a spring guide pin 100 which engages with oneend of the brake spring 90 extending into the cavity 38 in line with theshoe 88. The curved central portion of the shoe 88 is provided with areplaceable brake liner 102 for frictionally engaging thecircumferential Wall of the drum 86 when the spring 90 forcibly biasesthe shoe 88 against the rim of the drum. An adjusting screw 104 bearsagainst the spring 90 and may be turned within the threaded opening 106in the motor housing 14 to move the spring relative to the shoe 86thereby to preset the compressive force with which the spring 90 biasesthe shoe 88 and liner 102 against the drum 86. From the foregoing itwill be understood. that the brake is spring applied and may be adjustedto regulate the frictional braking force applied to the rotary drum 86.A preferred means for releasing the brake comprises a pressure fluidactuated piston 92 which is shiftable within a cylinder 103 defined bythe motor housing 16. It is contemplated that, upon energization of themotor 48 for driving in either direction, pressure fluid, will bedirected through suitable passages, not shown, in the motor housing tothe cylinder 108 for shifting the piston 92 in a direction to cause apiston stem 110 to compress spring 90 and to pivot the brake shoe 88 andthe liner 102 out of braking engagement with the shoe 86.

The preferred mode of operation of the illustrative hoist is as follows:Assuming that it is desired to lower the hoist body 10 to position thehook 24 for loading,

the operator grasps the handle 46 with his hand so that his thumboverlies the valve actuator 70. Upon depression of actuator 70, motivefluid is admitted to the motor 48 for driving the pinion shaft 74, theassociated reduction gearing, and the reel 77 in a direction whereby thecable 22 will pay out and the hoist body 10 will travel downwardly.Simultaneously with actuation of the motor 48, it is contemplated thatpressure fluid will be supplied to cylinder 102 to force the piston stem110 against the brake shoe 88 thereby compressing the spring 90 andreleasing the brake drum 86 for rotation with the pinion shaft 74 towhich it is splined. When the body 10 has been lowered to the desiredloading position, the actuator 70 is released thereby deenergizing themotor 48 and interrupting the fluid supply to the cylinder 108 so thatthe braking force of the brake spring 90 will be applied radially to thedrum 86 by means of the shoe 88 and the liner 102. The drum 86 willtransmit such braking force to the motor 48 and the reel 77 through theshaft 74. To raise the loaded hoist body, the valve actuator 68 isdepressed thereby energizing the motor 48 for reverse rotation andreleasing the brake assembly to permit the reel 77 to rotate for takingup the cable 22.

Prior to operating the hoist, the adjusting screw 104 should be presetWithin the opening 106 to effect compression of the spring 90sufficiently to assure that the braking force applied to the drum 86 issufiicient to prevent retograde movement of the motor 48, the pinionshaft 74, the reduction gearing, and the reel 77 under conditions ofmaximum anticipated loading of the hook An advantageous feature of thisinvention is realized by the provision of a brake drum 86 which isindependently supported and journaled by a main structural element ofthe hoist body, i.e. by the transverse wall 38 of the motor housing 16.This is in contradistinction to conventional practice wherein the brakedrum is journaled on and supported by the motor drive shaft or by adrive coupling member such as the pinion shaft 74. By inde pendentlyjournalling and supporting the brake drum 86 in the manner disclosedherein, the radially applied braking loads imparted to the drum by thespring 90 through shoe 88 are substantially isolated from the rotorbearings 56 and the pinion shaft 74. By this means, loading andresultant wear of the rotor bearings 56 due to braking forces aresubstantially reduced or completely eliminated; .and, bending stressesin the pinion shaft 74 tending to produce deleterious misalignment ofthe same are likewise reduced or eliminated.

Another distinguishing feature of this invention is the provision of amotor housing member having a cavity which conveniently receives boththe hoist motor and the brake assembly. As will be observed in FIG. 3,the motor 48 and the brake parts 86 and 88 are both disposed in a(common cavity 36 and in closely spaced coaxial relation to one another.This arrangement of the motor and the brake is particularly advantageouswhere minimizing the over-all length of the hoist body is an importantdesign consideration. Moreover, in accordance with the disclosedarrangement of the motor and brake, the brake can be located so that thebraking force produced thereby is applied to the motor pinion shaft 74at a point intermediate the ends thereof, i.e. between the driving motor48 and the driven reduction gearing, thereby greatly reducing normallyexpected inertia and reactance forces tending to produce potentiallydamaging torsional stress and deflection in the pinion shaft.

From the foregoing it will be seen that the disclosed hoist brakeassembly having a brake drum 86 journaled independently on a casingmember 14 of the hoist body 10 need not be disassembled from the hoistin order to disassemble either or both the motor 48 and the pinion shaft74 from the hoist. To replace or repair the motor 48, it is onlynecessary to remove the closure member 16 and to withdraw the motor 48axially from cavity 36 thereby disengaging the splined drivingconnection between the rotor sleeve extension 58 and the splined end 76of the pinion shaft 74. To disassemble the pinion shaft 74 from thebrake drum 86 in order to replace or repair any of the hoist partshoused in the gear housing 12, the gear housing is merely detached fromthe flange 32 of the motor housing 14 and withdrawn axially therebydisengaging the splined connection between the brake drum 86 and thesplined end 76 of the pinion shaft 74. Thus it Will be understood thateither or both the motor 48 and the pinion shaft 74 can-be disassembledfrom the brake assembly without disassembly of any of the parts of thebrake assembly. This novel coaction of the brake assembly with the hoistmotor 48 and with the motor pinion shaft '74 not only makes it easier todisassemble and reassemble the hoist parts, but also provides thisadvantage without disturbing a preset adjustment of the brake spring 90.Since the preadjusted setting of the brake spring need not be changed,repair of the hoist is made quicker and easier and all hazards due toimproper readjustment of the brake are avoided.

The exemplary hoist is adapted for actuation by pressure fluid, such ascompressed air; however, it is not intended that the invention belimited thereto. For example, an electric motor having suitable controlsfor effecting reverse rotation and associated solenoid means forreleasing the brake shoe 88 could be substituted for the disclosed motor48 and the brake releasing piston 92, respectively. Furthermore, thecable 22 could be replaced by any equivalent flexible tension membersuch as a chain. Moreover, it will be understood that the abovedescription and accompanying drawings comprehend only a general andpreferred embodiment of the invention and that various changes inconstruction, proportion, and arrangement of the elements thereof may bemade with out sacrificing any of the above enumerated advantages ordeparting from the scope of the appended claims.

What is claimed as new and useful is:

1. A rotary hoist comprising:

housing means having a cavity therein;

a rotary motor disposed in said cavity;

reel means for a flexible load bearing member;

drive means connecting said motor to said reel means:

brake means for said motor and said reel means;

said brake means being disposed in said cavity; said brake means havinga rotary element in brake force transmitting relation with said drivemeans; and

said rotary element being supported and journaled by said housing means,said housing means includes a transverse wall defining the closed end ofsaid cavity; said wall being provided with an aperture; said rotaryelement being disposed between said motor and said wall, and said rotaryelement being supported and jou-rnaled in said aperture.

5 6 2. The invention according to claim 1, wherein: 2,831,554 4/1958Reynolds 254-186 said drive means includes a shaft which penetrates said3,184,018 5/1965 Christison 254186 aperture and extends into saidcavity; and said motor and said shaft are held in relatively recip-FOREIGN PATENTS rocable, but nonrotatable relationship. 5 0,099 4/1956France.

References Cited by the Examiner EVON BLUNK, Primary Examiner- UNITEDSTATES PATENTS H. C. HORNSBY, Assistant Examiner.

2,496,754 2/1950 Schramm 254168

1. A ROTARY HOIST COMPRISING: HOUSING MEANS HAVING A CAVITY THEREIN; AROTARY MOTOR DISPOSED IN SAID CAVITY; REEL MEANS FOR A FLEXIBLE LOADBEARING MEMBER; DRIVE MEANS CONNECTING SAID MOTOR TO SAID REEL MEANS;BRAKE MEANS FOR SAID MOTOR AND SAID REEL MEANS; SAID BRAKE MEANS BEINGDISPOSED IN SAID CAVITY; SAID BRAKE MEANS HAVING A ROTARY ELEMENT INBRAKE FORCE TRANSMITTING RELATION WITH SAID DRIVE MEANS; AND SAID ROTARYELEMENT BEING SUPPORTED AND JOURNALED BY SAID HOUSING MEANS, SAIDHOUSING MEANS INCLUDES A TRANSVERSE WALL DEFINING THE CLOSED END OF SAIDCAVITY; SAID WALL BEING PROVIDED WITH AN APERTURE; SAID ROTARY ELEMENTBEING DISPOSED BETWEEN SAID MOTOR AND SAID WALL, AND SAID ROTARY ELEMENTBEING SUPPORTED AND JOURNALED IN SAID APERTURE.